Etang de la Gruere

The Etang de la Gruere sits at about a thousand metres on the Franches-Montagnes, and its water is the colour of strong tea - stained by humic acids from the peat around it, so that on still days the spruces and pines reflect almost black. It was dammed in the seventeenth century to drive a grain mill, which is where the name, from oat groats, comes from, and has since become one of the most important raised bog sites in the Jura, protected as a moorland of national importance. A boardwalk and path circle it in about forty minutes, kept off the peat itself. Sundews and cotton grass grow in the bog. The plateau around is Freiberger horse country, open pasture with solitary spruces and free-roaming horses, and the site is a short walk from that landscape.

The landscape

• Tea-dark water - peat acids staining the pond nearly black.
• A raised bog of national importance - sundews and cotton grass on the margins.
• A forty-minute boardwalk circuit - kept above the peat.
• Freiberger horse country - the open plateau pasture around it.

When to go

May to October; hard winters freeze it solid. Two hours.

Before you go

It is small - the circuit takes well under an hour. Stay on the boardwalk; the bog is the reason for the protection. Parking fills at weekends. Swimming is not permitted.

Nearby

Saignelegier and the Franches-Montagnes are around it; the Doubs is north.

Key facts